Ondansetron

In short. Ondansetron is a 5-HT3 receptor antagonist. FDA has approved drug products that contain it; a compounded ondansetron preparation is not FDA-approved. In TrueRoute it is ordered as a patient prescription that the prescriber signs.

What it is

The prescribing information FDA publishes for one approved line of ondansetron tablets, orally disintegrating tablets and oral solution describes ondansetron as a 5-HT3 receptor antagonist.

FDA status

Because FDA has approved drug products that contain ondansetron, FDA’s guidance on compounded drugs that are essentially copies applies: a 503A pharmacy may not compound, regularly or in inordinate amounts, a drug that is essentially a copy of a commercially available drug product. FDA ties the difference to a change that the prescriber determines makes a significant difference for the patient, documented on the prescription.

Compounded medications are not FDA-approved, and FDA does not review them for safety, effectiveness or quality.

How it is ordered in TrueRoute

Ondansetron is ordered as a patient prescription. The prescriber names the patient, chooses the product from your catalogue at your account’s price, reviews the order total and signs. Before anything is charged, TrueRoute checks what it can check, such as the prescriber’s licence in the patient’s state as attested and whether the product can be sent there, and selects the route under its written routing policy. Orders are filled by licensed pharmacies in our network.

Office-use and physician-use purchasing is a separate purchase-order flow with no patient attached, available once your account holds that program.

The forms and strengths your account can order, with their prices for your ship-to state, are shown in your catalogue once your account is set up. This page lists none, because what is carried changes.

What the prescriber decides

The prescription is the prescriber’s. They decide whether ondansetron is appropriate for the patient and set the product, quantity and directions. TrueRoute is software: it does not recommend a medication, a dose or a product, it does not dispense, and it does not practice medicine.

Every medication reference page · For clinics · How it works

Questions

Sources

1. FDA, Drugs@FDA prescribing information for ondansetron tablets, orally disintegrating tablets and oral solution (NDA 020103, 2021 label)
2. FDA, “Compounded drug products that are essentially copies of a commercially available drug product under section 503A”, final guidance (January 2018)
3. FDA, “Compounding and the FDA: questions and answers” (content current as of September 16, 2025)

Rules change. Confirm what applies to your clinic with your state board of pharmacy, your medical board and your own counsel.